Fluid hoist



1. P. HEIL. FLUID HOIST.

APPLICATION FILED APR-2,1919.

Patnted July 4, 1922.

3 SHEETSSHEET 1 J. P. HEIL.

FLUID HOIST.

APPLICATION FILED APR. 2. 1919.

Patented July 4, 1922.v

H (Item .1036.

J. P. HEIL.

FLUID HOIST.

APPLICATION FILED APR. 2, 1919.

Patented July 4, 1922..

3 SHEETSSHEET 3- 0127501 mead,

"ETED STATES JULIUS P. HEIL, OF MILWAUKEE, WISCONSIN.

FLUID HOIST.

To all whom it may concern:

Be it known that I, JULIUS P; HEIL, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Fluid Hoists, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification.

This invention relates to improvements in fluid hoists.-

It is one of the objects of the present invention to provide a fluid hoist more particularly, although not solely, adapted for operating the dump bodies of power driven trucks.

A further object of the invention is to provide a fluid hoist which may be easily used in connection with any standard make of truck and dump body, and which will not require any space between the body and the cab or seat of the truck.

A further object of the invention is to provide-a fluid hoist which will permit the positioning of the body with relation to the front and rear axles to more evenly distribute the load thereon and thereby increase the capacity of the truck.

A further object of the invention is to provide a fluid hoist in which the use of outside pipes or ducts are eliminated.

A further object of the invention is to provide a fluid hoist which is a unitary structure and self contained and has therefore a minimum number of parts and may be easily mounted on a truck.

A further object of the invention is to provide a fluid hoist which will automatically stop the further tilting of the truck body when said body has reached its predetermined dumping inclination.

A further object of the invention is to provide a .fluid hoist in which the pumping means may continue to operate without further elevation of the dump body of the truck when said dump body has reached its predetermined angle of unloading.

A further object of the invention is to provide a fluid hoist in which the truck body may be elevated to and be maintained in its upper position for an indefinite period while the parts continue to operate without injury to the hoist.

A further object of the invention is to provide a fluid hoist in which a plurality of Specification of Letters Patent.

Application filed April 2,

Patented July 4, 1922.

1919. Serial no. 288,872.

cylinders and pistons are used for elevating the truck body.

A further object of the invention is to provide a fluid hoist in which the piston itself serves to automatically stop the supply of the fluid medium to the pump when said piston has reached a predetermined position of rest.

A further object of the invention is to provide a fluid hoist which is of simple construction, is strong and durable and is well adapted for the purpose described.

With the above and other objects in view the invention consists of the improved fluid hoist and its parts and combinations as set forth in the claims, and all equivalents thereof.

In the accompanying drawings in which the same reference characters indicate the same parts in all of the views:

Fig. 1 is a side View of the rear portion of a motor truck provided with the improved fluid hoist, parts being broken away and the body portion being shown in tilted position by dotted lines:

Fig. 2 is a transverse sectional view taken on line 22 of Fig. 1, of the improved fluid hoist;

Fig. 3 is a vertical sectional view of one of the cylinders taken on line 3-3 of Fig. 2;

Fig. 4 is a vertical sectional detail view on a larger scale, of the upper end portion of one of the cylinders;

Fig. 5 is a vertical sectional detail View taken on line 5-5 of Fig. 2;

Fig. 6 is a horizontal sectional view on a smaller scale, taken on line 66 of Fi 5;

Fig. 7 is a similar sectional View ta en on line 7-7 of Fig. 5; and

Fig. 8 is a vertical sectional detail View on a larger scale of the transmission mechanism.

Referring to the drawings the numeral 10 indicates a portion of a motor truck, 11 the side members of the chassis or frame, 12 the cab or seat portion and 13 the tiltable load carrying body of the truck. Said body near its rear end portion is pivotally connected to the opposite side members 11 by pivot and bracket means 14.

The improved fluid hoist 15 comprises a pair of spaced cylinders 16 connected together at their lowerends by a lower tie bar per outer portions of.- the cylinders are pro vided with outwardly projecting portions 20 having alined trunnion recesses or sockets 20 for receiving the inwardly projecting trunnions 21 of the brackets 22 which rest on and are bolted to the side members 11 of the chassis. The cylinders are pivotally supported on said trunnions and depend downwardly therefrom and are provided with pistons 23 reciprocally positioned therein. The pistons are mounted on the lower end portions of piston rods or tubes 24 which extend upwardly through the upper closed ends of the cylinders and are provided with upper eyed ends 25. Said eyed ends are pivotally connected to the truck body he neath the bottom portion by a pivot rod 26 which extends transversely of said bottom portion and through the longitudinal reinforcing channel member 27 thereof. Said pivotal connections permit the piston rods and cylinders to tilt and aline with said pivotal connections while the truck body is traveling its arc of movement to unloading position.

The cylinders are formed with lower ports 28 and upper ports 29 which respectively charge or discharge the fluid medium from the cylinders below or above the pistons. The ports 28 are in communication with ducts 30 which are formed in the walls of the cylinders and lead upwardly from said ports 28 to a lower connecting and transversely extending pressure duct 31 formed in the conduit member 18. The upper ports 29 of the cylinders are of less height than the height of the pistons and are also in communication with an upper connecting transversely extending pump supply duct 32 formed in the conduit member 18 above the duct 31. The conduit member 18 is also provided with a valve bore 33 which is connected to the ducts 31 and 32 by by-pass ducts 31 and 32'. A plug valve 34 extending into the valve bore 33 is provided with an angular port 35 and the valve may be turned to register said port 35 with the by-pass ducts 31 and 32 and provide a communication therebetween for the flow of the fluid medium therethrough. This valve is turned to open communication between the by-pass ducts 31' and 32' when it is desired to lower the truck body.

A rotary gear pump 36 mounted on the conduit member 18 is positioned between the ducts 31 and 32 and is connected respectively to said ducts by inlet and outlet pump ports 37 and 38. The lower outlet port 38 is provided with a spring actuated ball check valve 38 opening outwardly from the pump. One of the gears of the pump is connected to and driven by the transmission 39 by a connecting rod or shaft 40 and the transmission of ower to the pump connecting rod is contro led by a controlling rod 41 and a lever 42. The plug valve 34 is also controlled by a rod 43 and a lever 44, both levers 42 and 44 being preferably located in the cab or adjacent the seat of the truck.

As considerable space within the cylinders is required to accommodate the piston rods when they are in their innermost position less fluid medium is used when the pistons are in their inner position than when in their outer positon and to supply the varying amounts a tank 45 is mounted on the upper end portions of the cylinders which is in communication with the upper end portions of said cylinders by openings or ports 46. The fluid medium flows by gravity from the tank to thecylinders when the pistons are moving upwardly. and is forced upwardly into the tank by the pistons when said pistons are moving downwardly.

The upper portions of the cylinders also have lead or starting ducts 47 formed therein which lead from the upper ends of the cylinder bores outwardly and downwardly to the upper ports 29 to initially supply the fluid medium to the cylinders above the pistons when said pistons are in their upper position and closing the said ports 29. and it is desired to permit said pistons to descend to their lower position. Said lead or starting ducts are provided with ball check valves 48 which open upwardly from the ports 47 and prevent the downward flow of the fluid medium therethrough.

In use the fluid hoist is mounted on a motor truck in the manner shown in Fig. 1 and when it is desired to dump the contents of the truck body the transmission controlling rod is operated to transmit motion from the transmission to the pump and the operation of the pump will draw the fluid medium from above the pistons and force it into the cylinders below the pistons and raise said pistons. The upward movement of the pistons will tilt the truck body connected thereto and when the pistons have reached their uppermost position they will close the upper ports 29 and thus automati cally shut off the supply of fluid medium or oil to the pump. The pump may continue to operate but as its supply of oil is cut off it cannot pump any more into the cylinders below the pistons and therefore the further upward movement of the pistons will automatically stop. This feature is very desirable in constructions of this kind as it eliminates any danger of damage to the hoist in the event that the operator inadvertently neglects to stop the operation of the pump. The pistons will remain in their upper position whether or not the pump is in operation. If it is now desired to lower the truck body the valve rod 43 is operated to open the valve 34 and when opened the oil in the cylinders can flow through the valve to the portions of the cylinders above the pistons and mamas thus permit the valved controlled descent of the pistons and the truckbody. Asthe ports 29 are closed by the pistons the Initial flow of oil above the pistons will be through the lead or starting ducts 47 until the pistons uncover the main up er ports 29, and when uncovered the flow w1ll be through said main ports. The speed of lowering the truck body is controlled by opening or closing more or less the port of the valve.

It is to be understood that one or any number of cylinders and pistons may be used without departing from the spirit and scope of the invention.

From the foregoing description it will be seen that the fluid hoist is of very simple construction and may be easil mounted on a motor truck, and is well a apted for the purpose described.

What I claim as my invention is:

1. A fluid hoist, comprising a pair of cylinders having ports at their opposite end portions, pistons within the cylinders and between the ports of the respect ve cyllnders and having piston rods extendlng through the cylinders, means connecting said piston rods together, a tank in communication with both cylinders, ducts connecting the ports of the cylinders together in pairs, a pump intersecting the pairs of ducts'between the respective ports thereof for movlng a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest, sald positions of rest of the pistons c los1ng the ports which are supplying the fluid medium to the pump and thereby automaticallystopping the movement of the pistons, and a valve controlled duct in communication with the ducts connecting the pairs of ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump.

2. A fluid hoist, comprising a pair of cylinders having ports at their opposite end portions, :1 lead port in each cylinder in communication with the cylinders and with one of the first mentioned ports of each cyl-- inder, pistons within the cylinders and between the ports of the respective cylinders and having ductless piston rods extending through the cylinders, means connecting said piston rods together, ducts connecting the ports of the cylinders together in pairs, :1 pum intersecting the pairs of ducts between the respective ports thereof for moving a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest. said positions of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons, and a valve controlled duct in communication with the ducts connecting the pairs of ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump. 7

3. A fluid hoist, comprising a pair of spaced cylinders having ports formed in their upper and lower end portions, pistons within the cylinders and between the ports of the respective cylinders and having ductless piston -rods extending through the cylinders, means connecting said iston rods together, a duct member connecting the cylin ers together and having ducts which connect the upper and lower ports together in pairs, a pump intersecting the duct member ducts for pumping a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest, said positions of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons, and a valve controlled by-pass duct in communication with the duct member ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump.

4. A fluid hoist, comprising a support, a pair of spaced cylinders fulcrumed on the support at their upper ends and connected together at their lower ends and having ports formed in their upper and lower end portions, a tank in communication with both cylinders, pistons within the cylinders and between the ports of the respective cylinders and having piston rods extending through the cylinders, a tiltable body positioned above the cylinders and connected to the upper end portions of the piston rods, a duct member connecting the cylinders together and having ducts which connect the upper and lower ports together in pairs, a pump mounted on the duct member and intersecting the ducts thereof for pumping 'a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest, said positions of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons, and a valve controlled duct in communication with the duct member ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing throughthe pump.

5. A fluid hoist comprising a su port, a pair of spaced cylinders fulcrume on the support at their upper ends and connected together at their lower ends and havin ports formed in their upper and lowerend portions, pistons within the cylinders and between the ports of the res ective cylinders and having piston ro s extending through the cylinders, a tiltable body positioned above the cylinders and connected to the upper end portions of the piston rods, a duct member connecting the cylinders together and having ducts which connect the upper and lower ports together in pairs, said cylinders also having lead ports in their upper ends above the upper ports first mentioned and in communication with the ducts of the duct member, a pump mounted on the duct member and intersecting the ducts thereof for pumping a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predeter ping t e movement 0 mined positions of rest, said positions of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons, and a valve controlled duct in communication with the duct member ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump.

6. A fluid hoist comprising a support, a pair of spaced cylinders fulcrumed on the support at their upper ends and connected together at their lower ends and having ports formed in their upper and lower end portions. pistons within the cylinders and between the ports of the respective cylinders and having piston rods extending through the cylinders, a tiltable body positioned above the cylinders and connected to the upper end portions of the piston rods, a duct member connecting the cylinders together and having ducts which connect the upper and lower ports together in pairs. said cylinders also having valve controlled lead ports in their upper ends above the upper ports first mentioned and in communication with the ducts of the duct member. a pump mounted on the duct member and intersecting the ducts thereof for pumping a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest, said positions of rest of the pistons closing the ports which are supplying the fluid medium to the ump and thereb automatically stopthe pistons, and a valve controlled duct in communication with the duct member ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump.

7. A fluid hoist, comprising a support, a tiltable body mounted thereon, a pair of cylinders fulcrumed on the support at their upperends and connected to ether at their lower ends and having ports ormed in their upper and lower end portions. a tank connected to both cylinders, pistons within the cylinders and between the ports of the respective cylinders and having ductless piston rods extending upwardly through the cylinders and having pivotal connections with the tiltable bod a duct member connected to the cyliniers and having ducts which connect the upper and lower ports together in pairs, said cylinders alsohaving check valve controlled lead ports in their upper ends above the first mentioned ports which are in communication with the cylinders and the ducts of the duct member, a pump mounted on the duct member and intersecting the ducts thereof for pumping a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest, said positions of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons. and a valve controlled duct in communication with the duct member ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump.

8. A fluid hoist, comprising a support, a tiltable body mounted thereon, a pair of cylinders fulcrumed on the support at their upper ends and connected together at their lower ends and having ports formed in their upper and lower end portions, a tank connected to both cylinders, pistons within the cylinders and between the ports of the respective cylinders and having piston rods extending upwardly through the cylinders and having pivotal connections with the tiltable body, a duct member connected to the cylinders and having ducts which connect the upper and lower ports together in pairs, said cylinders also having check valve. controlled lead ports in their upper ends above the first mentioned ports which are in communication with the cylinders and the ducts of the duct member, a pump mounted on the duct member and intersecting the ducts thereof for pumping a fluid medium within the cylinders from one side of the pistons to the other to move the piston to predetermined positions of rest, said positions of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons, a tank having openings in free communication with the cylinder bores for receiving, holding and returning to-the cylinders the at times surplus fluid medium, and a valve controlled duct in communication with the duct member ducts to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump.

9. A fluid hoist, comprising a support, a tiltable body mounted thereon. a pair of cylinders connected together at their lower ends and having fulcrum recesses adjacent their upper end portions, trunnions mounted on the support and extending into the remenace cesses, said cylinders also each having an upper and a lower port, a tank connected to both cylinders, a piston within each cylinder between the ports thereof and having a piston rod which extends upwardly through the cylinder, a pivotal connection between the upper ends of the piston rods and the tiltable body, a duct member connected to the cylinders and having upper and lower horizontally extending ducts, the upper ducts of the member being in communication with 'the upper ports of the cylinders and the lower duct of the member being in communication with the lower ports of the cylinders, a pump mounted on the .duct member and intersecting the ducts thereof for pumping a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest, said position of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons, said cylinders also having check valve controlled lead ports in their upper ends above the first mentioned ports which are in communication with the cylinders and the ducts of the duct member, said duct member also having a by-pass duct connecting the two member ducts together to permit the passage of the fluid medium from one side of each piston to the other side without passing through the pump, and a valve intersecting the by-pass duct and controlling the flow of the fluid medium therethrough.

10. A fluid hoist, comprising a support, a tiltable body mounted thereon, a pair of cylinders connected together at their lower ends and having fulcrum recesses adjacent their upper end portions, trunnions mounted on the support and extending into the recesses, said cylinders also each having an upper and and having upper and lower horizontally extending ducts, the upper ducts of the memher being in communication with the upper ports of the cylinders and the lower duct 1 of the member being in communication with the lower ports of the cylinders, a pump mounted on the duct member and intersecting the ducts thereof for pumping a fluid medium within the cylinders from one side of the pistons to the other to move the pistons to predetermined positions of rest, said positions of rest of the pistons closing the ports which are supplying the fluid medium to the pump and thereby automatically stopping the movement of the pistons, said cylinders also having check valve controlled lead ports in their upper ends above the first mentioned ports which are in communication with the cylinders and the ducts of the duct members, said duct member also having a by pass duct connecting the two member ducts together to permit the pas- Sage of the fluid medium from one side of each piston to the other side without passing through the pump, a tank mounted on the upper portions of the cylinders and having openings in communication with the cylinder bores for receiving, holding andreturning to the cylinders the at times surplus fluid medium, and a valve intersecting the by-pass duct and controlling the flow of the fluid medium therethrough.

In testimony whereof, I aflix my signature.

JULIUS P, HEEL. 

